Yeah, this guy might have convinced me to just KOS anyone looking for gas. Probably get some toilet paper out of the deal, at the very least.
Without going into too much detail about how some of us plan, if things get as bad as the pessimistic of us think may happen, pretty much in the end, trading will only be able to be done once most of the initial wave of dying is done & groups establish firm control of their areas, unless it's people you know really well & trust. Anybody offering to trade stuff to all and sundry without a very significant protection group, will be in danger of becoming among the first wave of dying as will be anybody a bit too visible that looks like they have stuff worth taking & places that look weak.
Which is why regardless if your plan is to stay or go or both, you need to prepare for the very real chance that you will have to make do with what you have and won't be able to buy or barter for what you want/need for a significant period of time, either because it's not available, or it's too dangerous among a number of other reasons.